Multistage evolution of continental collision orogen: A case study for western Dabie orogen

2009 ◽  
Vol 54 (15) ◽  
pp. 2568-2579 ◽  
Author(s):  
YuanBao Wu
Keyword(s):  
Continental Collision ◽  
Dabie Orogen

A record of ultrahigh temperature metamorphism in the Dabie orogen during Triassic continental collision

2019 ◽  
Vol 72 ◽  
pp. 54-64 ◽  
Author(s):  
Hengcong Lei ◽  
Haijin Xu ◽  
Junfeng Zhang ◽  
Hans-Joachim Massonne ◽  
Penglei Liu
Keyword(s):  
Continental Collision ◽  
Dabie Orogen ◽  
Ultrahigh Temperature

scholarly journals Rare allanite in granulitised eclogites constrains timing of eclogite to granulite facies transition in the Bhutan Himalaya

2021 ◽  
Author(s):  
Eleni Wood ◽  
Clare Warren ◽  
Nick Roberts ◽  
Tom Argles ◽  
Barbara Kunz ◽  
...  
Keyword(s):  
Granulite Facies ◽  
Continental Collision ◽  
Eastern Himalaya ◽  
Pb Isotope ◽  
Crustal Rocks ◽  
Metamorphic Terrane ◽  
Eclogite Facies ◽  
Lower Crustal ◽  
The Himalaya

During continental collision, crustal rocks are buried, deformed, transformed and exhumed. The rates, timescales and tectonic implications of these processes are determined by linking geochemical, geochronological and microstructural data from metamorphic rock-forming and accessory minerals. Exposures of lower orogenic crust provide important insights into orogenic evolution, but are rare in young continental collision belts such as the Himalaya. In NW Bhutan, eastern Himalaya, a high-grade metamorphic terrane provides a rare glimpse into the evolution and exhumation of the deep eastern Himalayan crust and a detailed case study for deciphering the rates and timescales of deep-crustal processes in orogenic settings. We have collected U-Pb isotope and trace element data from allanite, zircon and garnet from metabasite boudins exposed in the Masang Kang valley in NW Bhutan. Our observations and data suggest that allanite cores record growth under eclogite facies conditions (>17 kbar ~650°C) at ca. 19 Ma, zircon inner rims and garnet cores record growth during decompression under eclogite facies conditions at ca 17-15.5. Ma, and symplectitic allanite rims, garnet rims and zircon outer rims record growth under granulite facies conditions at ~9-6 kbar; >750°C at ca. 15-14.5 Ma. Allanite is generally considered unstable under granulite-facies conditions and we think that this is the first recorded example of such preservation, likely facilitated by rapid exhumation. Our new observations and petrochronological data show that the transition from eclogite to granulite facies conditions occurred within 4-5 Ma in the Eastern Himalaya. Our data indicate that the exhumation of lower crustal rocks across the Himalaya was diachronous and may have been facilitated by different tectonic mechanisms.

Sapphire-bearing magmatic rocks as indicators of the continental collision tectonic events: a case study of Uralian orogenic belt

2021 ◽  
Author(s):  
Elena Sorokina ◽  
Roman Botcharnikov ◽  
Yuriy Kostitsyn ◽  
Delia Rösel ◽  
Tobias Häger ◽  
...  
Keyword(s):  
Continental Collision ◽  
Orogenic Belt ◽  
Tectonic Activity ◽  
Alkaline Complex ◽  
Important Indicator ◽  
Tectonic Events ◽  
Magmatic Rocks ◽  
Orogenic Belts

<p>Gem corundum (mainly ruby) occurrences are commonly associated with orogenic belts. Corundum deposits of metamorphic origin are known as robust indicators of continent-continent collision tectonic events. Although sapphire-bearing primary magmatic deposits are also found in orogenic belts, their link to continental collision process remains poorly understood. Here we show that primary igneous blue sapphire occurrences in the Ilmenogorsky alkaline complex of Ilmen Mountains in Uralian orogenic belt are indicative of the continent-continent collision processes among Kazakhstania, Laurussia, and Siberia 330 – 250 Ma ago (Sorokina et al. 2017).</p><p>The results of geochemical, mineralogical, and geochronological research of corundum syenite pegmatites demonstrate that <em>in situ</em> primary magmatic corundum-bearing mineral assemblages can be used to evaluate the formation conditions and the time constraints of magmatic processes imposed by tectonic activity during orogenesis.</p><p>Thus, the corundum syenite pegmatites have recorded a multistage evolution of the Ilmenogorsky complex. They crystallized at temperatures of 700 – 750°C at 275 and 295 Ma ago (<em>in situ</em> LA-ICP-MS U-Pb zircon dating) within the timeframe of the continental collision of the Uralian orogeny. The isotopic signatures show a geochemical link of these deposits to nepheline syenites – miaskites of the main igneous body in Ilmenogorsky complex. While, some corundum syenite-pegmatites express the metamorphic overprint at temperatures of 700 – 780°C occurred 249 ± 2Ma ago (TISM Rb-Sr isotopy) during limited post-collision stretching period in the area of Ilmenogorsky complex (Sorokina et al. 2021). Hence, these results imply that primary magmatic corundum deposits can be used as an important indicator of continental collision events.</p><p>References:</p><div> <p>1.              Sorokina E.S., Botcharnikov R., Kostitsyn Yu.A., Rösel D., Häger T., Rassomakhin M.A., Kononkova N.N., Somsikova A.V., Berndt J., Ludwig T., Medvedeva E.V., Hofmeister W. (2021). Sapphire-bearing magmatic rocks trace the boundary between paleo-continents: a case study of Ilmenogorsky alkaline complex, Uralian collision zone of Russia. Gondwana research 2021 (in press).</p> <p>2.  Sorokina, E.S., Karampelas, S., Nishanbaev, T.P., Nikandrov, S.N., Semiannikov, B.S., (2017). Sapphire Megacrysts in Syenite Pegmatites from the Ilmen Mountains, South Urals, Russia: New Mineralogical Data. Canadian Mineralogist 55, 823–843</p> </div>

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